THE ALPHA LINES IN THE ‘‘K” SERIES TUNGSTEN 
SPECTRUM 
CHARLES CROFUTT 
{Abstract) 
According to Bohr’s theory of the atom, radiation takes place 
only when an electron goes from one orbit to an orbit closer the 
nucleus. If W represents the energy associated with an orbit, 
that is, the energy required to remove an electron from the orbit 
to infinity, the energy radiated when an electron goes from orbit 
(1) to orbit (2) will be = h, where orbit (2) is closer 
the nucleus. Assuming that an absorption frequency corresponds 
to the energy associated with a ring of the Bohr atom, the differ- 
ence between two absorption frequencies should give an emission 
frequency. 
Duane has measured one absorption frequency in the K region 
and three absorption frequencies in the L region. The difference 
between the K absorption frequency and the Li and Lo absorption 
frequencies respectively gives the Ka^ and the Ka^ lines. The 
difference between the K absorption frequency and the Lg absorp- 
tion frequency gives a result very close to the frequency of the as 
line. Duane did not succeed in resolving this Ka^ “doublet.” 
However, he did obtain evidence that it was a doublet. The peak 
obtained by him, using the ionisation method, was broader on one 
side than on the other. 
The present work was begun with the object of obtaining this 
ag line by means of the photographic method. The resolving pow- 
er of the X ray spectrometer was increased by using thin crystals, 
narrow slits, a greater distance between the crystal and the 
photographic plate, and by working on the second and third 
orders. This made it necessary to considerably prolong the 
time of exposure, in one case 11 days continuous operation. The 
front slit was .005 cm. in width and the thicknes of the crystal was 
.015 cm. The distance between the crystal and the plate holder 
was 60 cm. Since the line was not obtained on any of the 
plates the results seem to indicate that the intensity of the line 
is less than .1 that of the ag line, or it differs in wave length by less 
